单项选择题
A.highest-numbered IP interface
B.MAC address
C.device uptime
D.root port cost
单项选择题 Forthefollowingitems，whatisthemathematicalrelationshipbetweenthecommittedinformationrate（CIR），committedburst（Bc），andcommittedratemeasurementinterval（Tc）？（）
单项选择题 Forthefollowingprotocols，whichoneprovidesamechanismtotransparentlyinterceptandredirectCIFStrafficfromaclienttoalocalCiscoWidaAreaApplicationengine？（）
单项选择题 Policy-basedroutingallowsnetworkadministratorstoimplementroutingpoliciestoallowordenypathsbasedonallofthesefactorsexceptwhichone？（）